Pendulum-escapement



(No Model.) 2 Sheets- Sheet 1.

` L. ERIKSON.

PBNDULUM BSGAPEMENT.

Patented Apr. 19,1898.

l(No Model.) 2 Sheets-Sheet 2.

' L. ERIKSON.

PBNDULUM ESCAPBMENT.

No. 602,635. Patented Apr. l9, 1898.

. 6% M C7 w UNITED STATES PATENT CEEICE.

LAURENCE ERIKSON, OF EVANSTCN, ILLINOIS.

PENDULUNl-ESCAPENI ENT.

SPECIFICATION forming part of Letters Patent N 0. 602,635, dated. April 19, 1898.

Application filed November 6, 1897. Serial No. 657,592. (No model.)

T0 @ZZ whom it may concern:

Be it known that I, LAURENCE ERIKsoN, a citizen of the United States,residing at Evanston, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Escapements for Clocks, of which the following is a specification.

The present invention consists in the features of novelty that are hereinafter fully described with reference to the accompanying drawings, which are made a part of this speciiication and in which- Figure l is a front elevation of an escapement embodying the invention in its preferred form and showing' the parts in the positions which they occupy when the pendulum is at one extremity of its stroke. Figs. 2 and 3 are rear elevations of portions thereof on a larger scale, Fig. 2 showing the parts in the same positions as does Fig. l, while Fig. 3 shows the parts in the positions which they occupy when the pendulum is at the opposite extremity of its stroke. Fig. 4 is a front elevation of an escapement differing somewhat from that shown in the preceding gures, but embodying some features of the invention. Fig. 5 is a front elevation of an escapement differing somewhat from those shown in the preceding figures, but embodying some features of the invention. Fig. Gis a rear elevation of a portion thereof on a somewhat larger scale. Figs. 5 and 6 show the parts in the positions which they occupy when the pendulum is at opposite extremities of its stroke.

Referring first to Figs. l, 2, and 3, which show all of the several features of the invention in their preferred form, A represents the pendulum, B the escapement-wheel, and C the pallet. In the drawings the other parts ofthe works are not shown for the reason that their construction is fully understood by those skilled in the art and the present invention is in no wise concerned with them further than that they shall be of such construction that they will impart movement to the escapement-wheel in the direction of the arrow. The pallet C comprises two arms c cl, which form a V, and is secured to a rock-shaft D, which is suitably journaled in the frame and is provided with a stop c2 and a part cS having a surface in the nature of a cam which is adapted to receive impetus from the escapement-wheel and transmit it to the pendulum through the medium of the arm c of the pallet, the rock-shaft D, an arm E, secured to the' rock-shaft, and a tappet e, carried bythe arm, the pendulum being provided with a surface ain the nature of a cam for receiving impetus from the tappet e. The stop c2 preferably takes the form of a lug which is so disposed that when any tooth of the escapementwheel is in engagement with it the force thus exerted upon the pallet will be in a line which is radial with respect to its axis of motion, and the surface of the lug with which the tooth engages is preferably perpendicular to this line of force, so that the pressure of the escapement-wheel upon it will have no tendency whatever to oscillate thepallet. The part c3 preferably takes the form of a lug having a flat surface so disposed that as the stop c2 moves out of engagement with one tooth of the escapement-wheel the part cs will move into engagement with another tooth of the escapement-wheel, as shown in Fig. 2, the flat surface of the part c3 being so disposed that the pressure of the tooth of the escapementwheel against it will tend to oscillate the pallet and move it from the position shown in Figs. l and 2 to the position shown in Fig. 3. It is this movement of the pallet aided by gravity which causes the tappet c to move downward, and in doing so, acting upon the cam-surface a, it will give an impetus to the pendulum tending to throw it to the position shown in Fig. 3. When the tappet c is about to leave the cam a, the stop c2 will engage the escapement-wheel and prevent its further movement, permitting the pendulum to swing perfectly free until in moving from the position shown in Fig. 3 to that shown in Figs. 1 and 2 the cam CL comes in contact with the tappet c. After this takes place the continued movement of the pendulum toward the position shown in Figs. 1 and 2 will cause the cam a to lift the tappet c, thereby moving` the pallet from the position shown in Fig. 3 to the position shown in Figs. l and 2. At one side of the cam a the pendulum is provided with a rest a', which holds the tappet e up in opposition to the force which is exerted downward upon it by gravity and by reason of the engagement of the escapement-wheel with the ICO part c3, as shown in Fig. 2. By reason of this holding up of the tappet e only the alternate strokes of the pendulum are recorded, and the advantage of this is that with a pendulum having a half-second stroke each sweep of the secon ds-hand will represent a whole second. If, however, this should for any reason be undesirable, the rest a may be dispensed with and two cam-surfaces, such as a", used, as shown in Fig. 4L. In this case the secondshand will respond to every stroke of the pendulum instead of to every otherl stroke. In order to minimize the friction between the tappet e and the pendulum, the parts carried by the rock-shaft D are nearly balanced, and this may be accomplished by providing the arm E with an extension E', carrying a weight E2, and preferably this weight is adjustable, so that the balancing may be effected with accuracy. It is undesirable to have a preponderance on that side of the shaft which will tend to move the stop c2 out of engagement with the escapement-wheel, while, on the other hand, it is desirable that there be a very slight preponderance on the other side of the shaft, so as to insure that the parts shall have no tendency to move by gravity from the positions shown in Fig. 3 to the positions shown in Fig. 2. In order to limit the movement of the pallet by gravity and the force derived from the escapement-wheel, a fixed stop F may be secured to some suitable part of the frame.

In the form of the invention shown in Fig. 4 the pendulum is entirely free from the works, excepting during the momentary intervals of contact between the double cam a and the tappet e, and while this is an advantage which manifests itself in the more uniform movement of the pendulum it has the disadvantage that the clock will run only halt' as long as it will if only the alternate strokes of the pendulum be registered.

In Figs. 5 and 6 the pallet Cl and escapement-wheel B are of customaryconstruction. The pallet is secured to the rock-shaf t D, having the arm E, provided with a tappet c, and the arm E', provided with a counterweight E2, which preferably exactly balances the rock shaft D. Stops F' are also provided for limiting the movement of the rock-shaft in both directions. rlhe pendulum A is provided with two cam-surfaces c2, each of which corresponds in function to the cam-surface a, already described. rFliese cam-surfaces are disposed opposite each other and overlap, the stops F being so disposed that at whichever extremityof its stroke the pendulum may be the tappet e will lie in the path of one of the cam-surfaces a2, so that upon the return stroke said cam-surface will come in contact with the tappet and move the pallet to such position that the engaging tooth of the escapement-wheel will, through the medium of one or the other of its cam-faces c, give an impetus to the rock-shaft D. rl`his impetus causes the tappet e to be moved away from the cam-surface a2 which engaged it, as last aforesaid, and into contact with the opposite cam-surface a2, and thus give impetus to the pendulum. rIhe operation of this form of the invention is like that shown in Figs. l, 2, and 3 in that two complete strokes of the pendulum are necessary in order to permit the escapement-wheel to move through a given distance, and it is like that shown in Fig. 4C in that the pendulum is entirely free from the works excepting during the brief intervals when the pendulum is giving impetus to the tappet e or the tappet is giving impetus to the pendulum.

Having thus described my invention, the following is what I claim as new therein and desire to secure by Letters Patent:

I. In an escapement, the combination with the escapement-wheel, a pallet, a tappet, means connecting the pallet and tappet, of a pendulum having a cam-surface adapted to giveimpetus to and receive impetus from said tappet, and means for holding the escapement-wheel at rest while the cam-surface and tappet aforesaid are out of engagen'ient with each other, substantially as set forth.

2. In an escapement, the combination with an escapement-wheel, a pallet, a tappet, and means connecting the pallet and tappet, of a pendulum having' a cam-surface adapted to give impetus to and receive impetus from said tappet, and a rest carried by the pallet and adapted to engage said tappet for holding the pallet in engagement with the escapement-wheel, substantially as set forth.

3. In an escapement, the combination with an escapementwheel, of a pallet having the lug c provided with a single surface adapted to engage the teeth of the escapement-wheel for holding it at rest, the lug c having a single surface adapted to bc engaged by the teeth of the escapement-whcel said surface being in the nature of a cam so disposed that the pressure of the escapement-wheel thereon will oscillate the pallet, a pendulum, and means for transmitting movement from the pallet to the pendulum and from the pendulum to the pallet, substantially as set forth.

4. In an escapement, the combination with an escapement-wheel, a pallet, a tappet, means connecting the pallet and tappet, and means for counterbalancing them, of a pendulum having a cam-surface adapted to receive impetus from and impart impetus to said tappet, and means for holding the escapement-wheel at rest when the cam-surface and tappet aforesaid are out of engagement, substantially as setforth.

LAURENOE ERIKSON.

lVitnesses:

N. C. Gmnnnv, I. Cnoss.

IIO

IIS 

